Robotic surgical systems such as those used in performing minimally invasive surgical procedures offer many benefits over traditional open surgery techniques, including less pain, shorter hospital stays, quicker return to normal activities, minimal scarring, reduced recovery time, and less injury to tissue. Consequently, demand for minimally invasive surgery using robotic surgical systems is strong and growing.
One example of a robotic surgical system is the da Vinci® Surgical System from Intuitive Surgical, Inc., of Sunnyvale, Calif. The da Vinci® system includes a surgeon's console, a patient-side cart, a high performance 3-D vision system, and Intuitive Surgical's proprietary EndoWrist™ articulating instruments, which are modeled after the human wrist so that when added to the motions of the robot arm holding the surgical instrument, they allow a full six degrees of freedom of motion, which is comparable to the natural motions of open surgery.
The da Vinci® surgeon's console has a high-resolution stereoscopic video display with two progressive scan cathode ray tubes (“CRTs”). The system offers higher fidelity than polarization, shutter eyeglass, or other techniques. Each eye views a separate CRT presenting the left or right eye perspective, through an objective lens and a series of mirrors. The surgeon sits comfortably and looks into this display throughout surgery, making it an ideal place for the surgeon to display and manipulate 3-D intraoperative imagery.
A stereoscopic endoscope is positioned near a surgical site to capture left and right views for display on the stereoscopic video display. When an instrument is outside a viewing area on the display, however, the surgeon may not know how far away or in which direction the instrument is at the time. This makes it difficult for the surgeon to guide the instrument to the surgical site. Also, it may be disconcerting to the surgeon if the instrument unexpectedly appears in view. Even when an instrument is within the viewing area of the display, the surgeon may not know which instrument it is or which patient-side manipulator (e.g., robotic arm on the patient-side cart) the instrument is associated with. This makes it difficult, for example, for the surgeon to instruct a patient side assistant to replace the instrument with another during a surgical procedure.
In order to locate an instrument which is outside of a viewing area on the display, it may be necessary to move the endoscope until the instrument appears in the viewing area. In this case, if the surgical instrument is being guided to the surgical site, the cameras' zoom and focus controls may also require frequent adjustment, making the process tedious and time consuming for the surgeon. If it happens that the instrument is in the camera field of view (“FOV”), but outside of the viewing area, because of a zoom-in adjustment to the view, then a zoom-out adjustment may be performed so that the instrument is back in the viewing area. Such a zoom-out, however, may be undesirable when a delicate surgical procedure is being performed that requires close scrutiny by the surgeon.